The Associated Press reported the couples filed the lawsuit with the U.S. District Court in Fargo that challenges the state’s constitutional amendment that defines marriage as between a man and a woman and its refusal to recognize same-sex marriages legally performed in other states.

North Dakota had been the last state without gay nuptials in which same-sex couples had not filed a lawsuit seeking marriage rights since the U.S. Supreme Court last June struck down a portion of the Defense of Marriage Act.

The AP reported that Josh Newville, a Minneapolis lawyer, is representing the North Dakota couples. He filed a federal lawsuit last month on behalf of six same-sex couples in neighboring South Dakota who are seeking marriage rights in their state.